Abstract. This is a revised application for a Mentored Research Scientist Development Award (K01) to support the career development of Dr. Ryan Vetreno as an independent academic research scientist in the field of alcohol research. The applicant?s career and research training will be supervised by an outstanding mentoring team and supported by strong institutional commitment to the candidates? career development. Humans typically begin drinking during adolescence when the brain is maturing and adolescent drinking behavior is characterized by the consumption of large quantities of alcohol in a heavy binge-like intermittent fashion (e.g., weekend drinking). Preclinical models of adolescent binge drinking reveal persistent reductions of basal forebrain cholinergic neurons, diminished hippocampal excitatory neurotransmission, and impaired reversal learning in adulthood. Using the adolescent intermittent ethanol (AIE) model of human adolescent binge drinking, Dr. Vetreno discovered increased expression of the innate immune receptor Toll-like receptor 4 (TLR4), the endogenous TLR4 agonist high-mobility group box 1 (HMGB1), and multiple proinflammatory signaling molecules that persist in the adult brain. The causal relationship between AIE-induced HMGB1-TLR4 innate immune induction and subsequent adult neuropathology is unknown. In his revised application, Dr. Vetreno proposes to test the mechanistic hypothesis that AIE induction of HMGB1-TLR4 signaling causes degeneration of adolescent basal forebrain cholinergic neurons leading to hippocampal dysfunction in adulthood. In order to fully test this hypothesis, Dr. Vetreno and his Mentors have devised a comprehensive mentoring and research plan that will provide him with protected time for intensive training in ex vivo slice culture, electrophysiology, and chemogenetics. The training outlined in this proposal will provide the candidate the means to develop a successful, independent research laboratory at the University of North Carolina at Chapel Hill that will be at the forefront of adolescent alcohol and neuroimmune research. Together, these studies will advance our understanding of the mechanisms underlying persistent changes to adolescent brain development associated with underage binge drinking, provide innovative targets for the development of therapeutic interventions, and will markedly advance Dr. Vetreno?s career development and scientific independence.